This invention relates to pile material for brushes, carpeting and the like, and more particularly to a method of making such pile material.
This invention involves an imrovement over the prior art method of making pile material, such as discussed for example in U.S. Pat. Nos. 3,085,922 and 3,359,147, comprising the steps of providing a bundle of pile strands impregnated with a binder holding the strands together, cutting the bundle into slabs or wafers, bonding a backing member on the slabs, and then removing the binder material from the slabs. In U.S. Pat. No. 3,085,922, soluble binder material, such as alcohol-soluble terpolyamide resin, is used and this binder material is removed from the slab, after the backing member has been bonded thereto, by rinsing it in the solvent. In U.S. Pat. No. 3,359,147, water is applied to the strands and the wetted bundle is frozen to solidify it. The water is removed from the slab, after the backing member has been bonded thereto, by heating the frozen slab and allowing the water to drain. The use of binder materials in the prior art method thus limits the practice of the method to materials which are compatible with the binders. A further problem with the prior art methods is that the operations of applying a binder to the pile strands and then removing it from the strands are relatively time consuming. Consequently, pile material made according to the prior art method is relatively costly.